I’ve seen three different trigger mods for the Ruger LC9s that people have installed but I haven’t seen any information from people who have installed more than one mod. I decided to install all three mods to see if they were compatible with each other. The mods are:
MCARBO trigger spring kit, which replaces the striker spring, striker block spring and the trigger return spring.
PRP trigger kit, which replaces the sear and trigger pivot with a modified sear and trigger pivot.
Aegis short stroke trigger, which replaces the trigger with a modified trigger. The Aegis trigger is not compatible with the magazine safety, which must be removed when the trigger is installed.
I installed all three mods at the same time, so I can’t tell how much of an effect each mod had individually. Total installation time was about an hour.
I ran into two problems. The modified sear in the PRP kit prevented the safety from working. I contacted PRP support and they immediately sent out a replacement which worked fine. I was very pleased with PRP’s support.
The second problem I had was that after all three mods were installed, the trigger wouldn’t fire on every pull. More accurately, you couldn’t pull the trigger back far enough to fire. The trigger safety was keeping it from firing. I ended up reinstalling the original return spring and everything worked perfectly.
Unfortunately, I don’t have access to a scale to measure the pull weight, so I took it to a local gunsmith to have it measured. The gunsmith was a real old-timer (I’m 66) and he had an old mechanical scale. Prior to the mods being installed, he measured “about 4 and a half” pounds. After the mods were installed, he measured “about 4” pounds.
I’m not an expert, but I question his measurements. To me, the trigger pull feels significantly less than it did pre-mod. I wish I had access to a good, digital scale to get an accurate measurement.
What I was able to measure was the trigger pull length and trigger reset length. Pre-mod, there was 3/8" dead length before you felt any resistance. From the point of first resistance to the firing point was 5/16". From the firing point back to the reset point was 7/16". Total trigger travel was 11/16", or just short of 3/4"
Post-mod the dead length is only 1/8". From the point of first resistance to the firing point is only 3/16". From the firing point back to the reset point is only 3/16". Total trigger travel is 5/16", or just over 1/4" or not quite 1/2" less than the pre-mod travel!
As you can see, the trigger travel is significantly less after the mods were installed as is the pull weight. I also think the replacement trigger has a much better feel and is much more attractive. (I opted for the red anodized trigger.) According to the manufacturer, it also eliminates the “trigger bite” that some people have experienced.
Hopefully, this information will be helpful to anyone considering installing one or more of these options.